This application relates generally to turbochargers for internal combustion engines, and more particularly relates to recirculation valves used with the turbocharger compressor for allowing some portion of the already-compressed air from the compressor discharge to be recirculated back to the compressor inlet.
Using a recirculation valve (RCV) with a turbocharger compressor to recirculate a portion of the already-compressed air back to the compressor inlet is a generally known strategy for delaying the onset of surge of the compressor to a lower flow rate at a given pressure ratio, or to a higher pressure ratio at a given flow rate. One drawback of the RCV, however, is that it tends to be a source of aerodynamically induced noise.